Buckley, who joined the broadcaster as its executive vice-president and commercial director just 18 months ago, replaces Cotton, who has been named as the executive vice-president and general counsel of the CNBC parent NBC Universal.
The promotion takes place with immediate effect. Buckley has been charged with expanding CNBC Europe's locally produced European programming including coverage from the leading European financial centres, increasing its distribution and developing additional local-language affiliates.
He will report to the board of CNBC International, a joint venture between NBC Universal and Dow Jones.
Pamela Thomas-Graham, the president and chief executive of CNBC, said Buckley has proven skills in running pan-European TV stations. Before joining CNBC Europe, he worked in a variety of senior roles at Turner Broadcasting Europe, including the post of executive vice-president of news networks and UK managing director. "I look forward to him taking the channel to greater heights going forward," she said.
Buckley added: "CNBC Europe is an unmatched product with a highly valuable and difficult-to-reach audience. My new role gives me the remit to not only build the channel on a pan-European basis, but also identify new opportunities to maximise the business in terms of revenue and audience growth."